previous commit introduced a bug in Barrett reduction

* Enable KAT testing for Falcon
* Prefix all algorithms with PQC_ALG_SIG/KEM_

Pulls SIKE/p434 from CECPQ2 implementation
changed to use SHAKE instead of SHA2

In order to enable all KAT tests, the AES based
DRBG is need (for seed expansion). This PR adds
port of DRBG, initialy written by NIST.

Afterwards, the katrunner is modified to enable
key generation, encapsulation and signing KATs.

Testing of NTRU prime is disabled, as it doesn't
pass KAT tests now. The tests for SPHINCS+ are
now very slow.